Silicon-containing polytrimethylene homo- or copolyether composition

ABSTRACT

Processes for preparing silicon-containing polytrimethylene homo- or copolyethers, wherein at least a portion of the polymer end groups are silicon-containing end groups, are provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.12/079,612, filed Mar. 27, 2008, which is a continuation-in-part of U.S.patent application Ser. No. 11/064,649 filed Feb. 23, 2005.

FIELD OF THE INVENTION

This invention relates to processes for preparing polytrimethylene homo-or copolyethers having silicon-containing end groups.

BACKGROUND OF THE INVENTION

In UV curable cationic coatings, photoinitiators generate cationicspecies, which then function as catalysts for cationic polymerization.Epoxides, in particular cycloaliphatic epoxides, are the major reactivemonomer/oligomers used for cationic UV cured coatings.

Typically, two types of crosslinkers are available for these coatings,low molecular weight alcohols and high molecular weight polyols. Highmolecular weight polyol crosslinkers, such as polyester, polyether, orcaprolactone polyols, provide excellent flexibility; however, they aregenerally viscous, and as a consequence increase application relatedproblems. Low molecular weight alcohols can reduce the viscosity of thecoating formulations. However, they are volatile and lack theflexibility needed for most coating applications.

Homo- or copolyethers of 1,3-propanediol also can be used ascrosslinkers for cationic UV curable coatings. However, they would havea greater effect if their functionality could be increased from theoriginal 2 (i.e., 2 hydroxyls per molecule). Moreover, conversion of thehydroxyl end groups to a non-hydrogen bonding species would also serveto reduce viscosity.

U.S. Pat. No. 3,833,512 discloses organosilicon polymers containingmonomeric units (A), (B) and (C) where (A) is an inorganic tetravalentsilicon containing units, where all valencies of the Si atoms aresaturated by oxygen linkages, (B) is polyvalent silicon containing unitswhere 2-3 valencies of the silicon are linked to oxygen and at least 1is linked to a carbon atom of an organic group containing apoly(oxyalkylene) chain, and (C) is monovalent silicon containing unitswhere 1 valency is linked to oxygen and the other 3 are saturated bymonovalent organic compounds, the mole ratio (A) to (B) to (C) being0.4-2:1:0.2-2 respectively.

U.S. Pat. No. 6,737,482 discusses curable resin compositions comprising:(1) a reactive silicon group containing polyoxyalkylene polymer andepoxy resin, wherein the introduction rate of the reactive silicon intoa molecular chain terminus is not less than 85% as analyzed by NMRspectroscopy, and (2) an epoxy resin.

SUMMARY OF THE INVENTION

One aspect of the present invention is a process for preparing asilicon-containing polytrimethylene homo- or copolyether comprising:providing reactants comprising:

-   (a) polytrimethylene homo- or copolyether ether glycol, wherein from    about 50 to 100 mole mole percent of the repeating units of the    polytrimethylene homo- or copolyether are trimethylene ether units,    and wherein the polytrimethylene homo- or copolyether has an Mw/Mn    ratio of 1.7 or greater; and-   (b) a silicon-containing reactant of the formula: Si(W)(X)(Y)(Z),    where W, X and Y are groups that are easily displaceable from    silicon by reaction with water and/or alcohols, and Z is selected    from the group consisting of: (i) C1-C20 linear or branched alkyl    groups, (ii) cycloaliphatic groups, (iii) aromatic groups, each of    (i), (ii) and (iii) being optionally substituted with a member    selected from the group consisting of O, N, P and S, (iv) hydrogen,    and (v) groups that are easily displaceable from silicon by water    and/or alcohol; and-   (c) contacting said polytrimethylene homo- or copolyether ether    glycol reactant in (a) with said silicon-containing reactant in (b)    at elevated temperature.

DETAILED DESCRIPTION

Unless stated otherwise, all percentages, parts, ratios, etc., are byweight. Trademarks are shown in upper case. Further, when an amount,concentration, or other value or parameter is given as either a range,preferred range or a list of upper preferable values and lowerpreferable values, this is to be understood as specifically disclosingall ranges formed from any pair of any upper range limit or preferredvalue and any lower range limit or preferred value, regardless ofwhether ranges are separately disclosed. Where a range of numericalvalues is recited herein, unless otherwise stated, the range is intendedto include the endpoints thereof, and all integers and fractions withinthe range. It is not intended that the scope of the invention be limitedto the specific values recited when defining a range.

The silicon-containing polytrimethylene homo- or copolyethers of theinvention are preferably prepared by reaction of one or morepolytrimethylene homo- or polyether glycols with a silicon-containingreactant. Polytrimethylene homo- or polyether glycols are preferablyprepared by polycondensation of monomers comprising 1,3-propanediol,thus resulting in polymers or copolymers containing: —˜CH₂CH₂—CH₂—O—}—,or trimethylene ether repeating units. For the purposes of theinvention, at least 50% of the repeating units are trimethylene etherunits. Preferably, from about 75 to 100, more preferably from about 90to 100, and most preferably from about 99 to 100 mole percent of therepeating units are trimethylene ether units. Thus, minor amounts ofother polyalkylene ether repeating units may be present also. Preferablythese are derived from aliphatic diols other than 1,3-propanediol.Examples of typical aliphatic diols that may used include those derivedfrom aliphatic diols, for example ethylene glycol, 1,6-hexanediol,1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol,1,12-dodecanediol, 3,3,4,4,5,5-hexafluoro-1,5-pentanediol,2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol, and 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-hexadecafluoro-1,12-dodecanediol, cycloaliphaticdiols, for example 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol andisosorbide. A preferred group of aliphatic diols is selected from thegroup consisting of ethylene glycol, 2-methyl-1,3-propanediol,2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol,2-ethyl-2-(hydroxymethyl)-1,3-propanediol, 1,6-hexanediol,1,8-octanediol, 1,10-decanediol, isosorbide, and mixtures thereof. Themost preferred diol other than 1,3-propanediol is ethylene glycol.

The polytrimethylene homo- or copolyethers that are the basis for theinvention described herein are preferably selected from the groupconsisting of polytrimethylene ether, poly(trimethylene-ethylene ether),random poly(trimethylene ether ester), and mixtures thereof. Thesilicon-containing derivatives of these, which are the subject of theinvention, are preferably prepared by reaction of the correspondingglycols (i.e., polyethers with hydroxyl end groups) with asilicon-containing reactant. The 1,3-propanediol employed for preparingthe polytrimethylene homo- or copolyether glycols that are employed forreaction with silicon-containing reactants may be obtained by any of thevarious chemical routes or by biochemical transformation routes, thelatter resulting in biologically produced 1,3-propanediol. Preferredroutes are described in U.S. Pat. Nos. 5,015,789, 5,276,201, 5,284,979,5,334,778, 5,364,984, 5,364,987, 5,633,362, 5,686,276, 5,821,092,5,962,745, 6,140,543, 6,232,511, 6,277,289, 6,297,408, 6,331,264 and6,342,646, U.S. patent application Ser. No. 10/839,188, filed May 5,2004, US 2004-0260125A1 and US 2004-0225161 A1, all of which are intheir entireties.

Biologically produced 1,3-propanediol represents a new feedstock foruseful polymers. Polymer derived at least partly from biologicallyproduced 1,3-propanediol may be distinguished from polymer derived fromall petrochemical carbon on the basis of dual carbon-isotopicfingerprinting. Additionally, the specific source of biosourced carbon(e.g. glucose vs. glycerol) can be determined by dual carbon-isotopicfingerprinting. This method usefully distinguishes otherwisechemically-identical materials, and apportions carbon in the copolymerby source (and possibly year) of growth of the biospheric (plant)component. The isotopes, 14C and ¹³C, bring complementary information tothis problem. The radiocarbon dating isotope (¹⁴C), with its nuclearhalf life of 5730 years, clearly allows one to apportion specimen carbonbetween fossil (“dead”) and biospheric (“alive”) feedstocks [Currie, L.A. “Source Apportionment of Atmospheric Particles,” Characterization ofEnvironmental Particles, J. Buffle and H. P. van Leeuwen, Eds., 1 ofVol. I of the IUPAC Environmental Analytical Chemistry Series (LewisPublishers, Inc) (1992) 3-74]. The basic assumption in radiocarbondating is that the constancy of 14C concentration in the atmosphereleads to the constancy of 14C in living organisms. When dealing with anisolated sample, the age of a sample can be deduced approximately by therelationship t=(−5730/0.693)In(A/A₀), where t=age, 5730 years is thehalf-life of radiocarbon, and A and Ao are the specific 14C activity ofthe sample and of the modern standard, respectively [Hsieh, Y., SoilSci. Soc. Am J., 56, 460, (1992)]. However, because of atmosphericnuclear testing since 1950 and the burning of fossil fuel since 1850,14C has acquired a second, geochemical time characteristic. Itsconcentration in atmospheric CO2—and hence in the livingbiosphere—approximately doubled at the peak of nuclear testing, in themid-1960s. It has since been gradually returning to the steady-statecosmogenic (atmospheric) baseline isotope rate (¹⁴C/¹²C) of ca.1.2×10⁻¹², with an approximate relaxation “half-life” of 7-10 years.(This latter half-life must not be taken literally; rather, one must usethe detailed atmospheric 30 nuclear input/decay function to trace thevariation of atmospheric and biospheric ¹⁴C since the onset of thenuclear age.) It is this latter biospheric ¹⁴C time characteristic thatholds out the promise of annual dating of recent biospheric carbon. ¹⁴Ccan be measured by accelerator mass spectrometry (AMS), with resultsgiven in units of “fraction of modern carbon” (f_(M)). fM is defined byNational Institute of Standards and Technology (NIST) Standard ReferenceMaterials (SRMs) 4990B and 4990C, known as oxalic acids standards HOxIand HOxII, respectively. The fundamental definition relates to 0.95times the ¹⁴C/¹²C isotope ratio HOxI (referenced to AD 1950). This isroughly equivalent to decay-corrected pre-industrial Revolution wood.For the current living biosphere (plant material), f_(M)1.1.

The stable carbon isotope ratio (^(13C)/¹²C) provides a complementaryroute to source discrimination and apportionment. The ¹³C/¹²C ratio in agiven biosourced material is a consequence of the ¹³C/¹²C ratio inatmospheric carbon dioxide at the time the carbon dioxide is fixed andalso reflects the precise metabolic pathway. Regional variations alsooccur. Petroleum, C3 plants (the broadleaf), C4 plants (the grasses),and marine carbonates all show significant differences in 13C/¹²C andthe corresponding 8¹³C values. Furthermore, lipid matter of C3 and C4plants analyze differently than materials derived from the carbohydratecomponents of the same plants as a consequence of the metabolic pathway.Within the precision of measurement, 13C shows large variations due toisotopic fractionation effects, the most significant of which for theinstant invention is the photosynthetic mechanism. The major cause ofdifferences in the carbon isotope ratio in plants is closely associatedwith differences in the pathway of photosynthetic carbon metabolism inthe plants, particularly the reaction occurring during the primarycarboxylation, i.e., the initial fixation of atmospheric CO₂. Two largeclasses of vegetation are those that incorporate the “C₃” (orCalvin-Benson) photosynthetic cycle and those that incorporate the “C4”(or Hatch-Slack) photosynthetic cycle. C3 plants, such as hardwoods andconifers, are dominant in the temperate climate zones. In C3 plants, theprimary CO2 fixation or carboxylation reaction involves the enzymeribulose-1,5-diphosphate carboxylase and the first stable product is a3-carbon compound. C4 plants, on the other hand, include such plants astropical grasses, corn and sugar cane. In C4 plants, an additionalcarboxylation reaction involving another enzyme, phosphoenol-pyruvatecarboxylase, is the primary carboxylation reaction. The first stablecarbon compound is a 4-carbon acid which is subsequently decarboxylated.The CO2 thus released is refixed by the C3 cycle. Both C4 and C3 plantsexhibit a range of 13C/¹²C isotopic ratios, but typical values are ca.−10 to −14 per mil (C₄) and −21 to −26 per mil (C₃) [Weber et al., J.Agric. Food Chem., 45, 2942 (1997)]. Coal and petroleum fall generallyin this latter range. The 13 C measurement scale was originally definedby a zero set by pee dee belemnite (PDB) limestone, where values aregiven in parts per thousand deviations from this material. The “8¹³C”,values are in parts per thousand (per mil), abbreviated °/o., and arecalculated as follows:

δ¹³ C = [( ¹³C/¹²C)_(sample) − ( ¹³C/¹²C)_(standard)/( ¹³C/¹²C)_(standard)] × 100%

Since the PDB reference material (RM) has been exhausted, a series ofalternative RMs have been developed in cooperation with the IAEA, USGS,NIST, and other selected international isotope laboratories. Notationsfor the per mil deviations from PDB is &³C. Measurements are made on CO2by high precision stable ratio mass spectrometry (IRMS) on molecularions of masses 44, 45 and 46.

Biosourced 1,3-propanediol and resulting polyols may be completelydistinguished from their petrochemical derived counterparts on the basisof ′4 C (fm) and dual carbon-isotopic fingerprinting, indicating newcompositions of matter. In fact, a U.S. patent on this new compositionof matter was granted on Jan. 30, 2007 (U.S. Pat. No. 7,169,588).

The most preferred source of 1,3-propanediol is a fermentation processusing a renewable biological source. As an illustrative example of astarting material from a renewable source, biochemical routes to1,3-propanediol (PDO) have been described that utilize feedstocksproduced from biological and renewable resources such as corn feedstock. For example, bacterial strains able to convert glycerol into1,3-propanediol are found e.g., in the species Klebsiella, Citrobacter,Clostridium, and Lactobacillus. The technique is disclosed in severalpatents, including, U.S. Pat. Nos. 5,633,362, 5,686,276, and 5,821,092.In U.S. Pat. No. 5,821,092, Nagarajan et al. disclose, inter alia, aprocess for the biological production of 1,3-propanediol from glycerolusing recombinant organisms. The process incorporates E. coli bacteria,transformed with a heterologous pdu diol dehydratase gene, havingspecificity for 1,2-propanediol. The transformed E. coli is grown in thepresence of glycerol as a carbon source and 1,3-propanediol is isolatedfrom the growth media. Since both bacteria and yeasts can convertglucose (e.g., corn sugar) or other carbohydrates to glycerol, theprocess of the invention provided a rapid, inexpensive andenvironmentally responsible source of 1,3-propanediol monomer.

The 1,3-propanediol starting material for the present invention may alsocontain small amounts, preferably no more than about 20%, morepreferably no more than about 10%, by weight, of the starting material,of comonomer diols in addition to the reactant 1,3-propanediol or itsdimers and trimers without detracting from the products and processes ofthe invention. Examples of preferred comonomer diols include ethyleneglycol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propane diol andC₆-C₁₂ diols such as 2,2-diethyl-1,3-propane diol,2-ethyl-2-(hydroxymethyl)-1,3-propane diol, 1,6-hexanediol,1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,4-cyclohexanediol,and 1,4-cyclohexanedimethanol. A more preferred comonomer diol isethylene glycol. Preferably the 1,3-propanediol used as the reactant oras a component of the reactant will have a purity of greater than about99% by weight as determined by gas chromatographic analysis.

Methods for preparation of the first preferred polytrimethylene homo- orcopolyether glycol, polytrimethylene ether glycol, by dehydration of1,3-propanediol or by ring opening polymerization of oxetane are wellknown in the art.

U.S. Pat. No. 2,520,733, discloses polymers and copolymers oftrimethylene glycol of molecular weight from about 100 to about 10,000and a process for the preparation of these polymers from 1,3-propanediolin the presence of a dehydration catalyst such as iodine, inorganicacids (e.g. sulfuric acid) and organic acids. U.S. Pat. No. 3,326,985,discloses a process for forming a polytrimethylene ether glycol havingan average molecular weight of 1,200-1,400. First, polytrimethyleneether glycol which has an average molecular weight of about 900 isformed using hydriodic acid dehydration catalyst. This is followed by anafter treatment which comprises vacuum stripping the polyglycol at atemperature in the range of 220-240° C. and at a pressure of 1-8 mm Hgin a current of nitrogen for from 1-6 hours. U.S. Pat. No. 6,720,459,which is incorporated herein by reference, discloses a continuousprocess for preparation of polytrimethylene ether glycol from1,3-propanediol using a polycondensation catalyst, preferably an acidcatalyst. The process provides high purity polytrimethylene ether glycolhaving a number average molecular weight of at least about 1,000. U.S.Patent Application Publication No. 2002/0007043, describespolytrimethylene ether glycol obtained from acid catalyzedpolymerization of 1,3-propanediol reactant selected from the groupconsisting of 1,3-propanediol and/or its oligomers or prepolymers havinga degree of polymerization of 2 to 9. The polymerization product issubjected to a purification process comprising (1) a hydrolysis step tohydrolyze the acid esters formed during the acid catalyzedpolymerization, (2) phase separation and water extraction steps toremove the soluble acid catalyst, generating an organic phase and awaste aqueous phase, (3) a base treatment of the organic phase toneutralize and precipitate the residual acid present, and (4) drying andfiltration of the polymer to remove residual water and solids. Theprocess provides high purity polytrimethylene ether glycol having anumber average molecular weight of at least about 1,000.

Polytrimethylene ether glycols having molecular weights lower than about1,000 are preferably prepared by a process that avoids the water washingstep conventionally used in purification, because the water washing maycause the loss of significant amounts of water sensitive oligomericpolytrimethylene ether glycol. For this reason a preferred method ofpreparation for material of these low molecular weights avoids thehydrolysis step. Such a process is described in U.S. patent applicationSer. No. 10/871,622, filed Jun. 18, 2004. The process consists of (a)polycondensing 1,3-propanediol or its dimers or trimers in the presenceof an acid polycondensation catalyst at a temperature of at least about150° C. to obtain a polytrimethylene ether glycol reaction mixture; (b)adding to the reaction mixture substantially water-insoluble base toneutralize the acid polycondensation catalyst and obtain a neutralizedreaction mixture, (c) contacting the neutralized reaction mixture withfilter aid having a permeability no greater than about 0.150 Darcy, and(d) separating the polytrimethylene ether glycol from the filter aid, toobtain polytrimethylene ether glycol that is essentially free of endgroups derived from the acid catalyst.

The second preferred polytrimethylene homo- or copolyether glycol foruse in preparing the products of the invention,poly(trimethylene-ethylene ether)glycol, may be prepared by methodsdisclosed in U.S. Patent Application Publication No. 2004/0030095. Asdisclosed there, the poly(trimethylene-ethylene ether)glycol may beprepared by a process comprising the steps of: (a) providing1,3-propanediol reactant, ethylene glycol reactant and acidpolycondensation catalyst; and (b) polycondensing the reactants to forma poly(trimethylene-ethylene ether)glycol. It may also be preparedcontinuously or semi-continuously using the procedure of U.S. PatentApplication Publication No. 2002/10374. The poly(trimethylene-ethyleneether)glycols are preferably prepared using at least about 1 mole %,preferably at least about 2 mole % and more preferably at least about 10mole %, and preferably up to about 50 mole %, more preferably up toabout 40 mole %, and most preferably up to about 30 mole % of ethyleneglycol reactant based on the total amount of 1,3-propanediol andethylene glycol reactants. The poly(trimethylene-ethylene ether)glycolsare preferably prepared using up to about 99 mole %, preferably up toabout 98 mole %, and preferably at least about 50 mole %, morepreferably at least about 60 mole %, and most preferably at least about70 mole %, of 1,3-propanediol based on the total amount of1,3-propanediol and ethylene glycol reactants.

The third preferred 1,3-propanediol based homo- or copolyether glycolfor use in preparing the products of the invention is randompolytrimethylene ether ester. A preferred method for preparation of therandom polytrimethylene ether esters is presented in detail in U.S. Pat.No. 6,608,168. The esters are prepared by polycondensation of1,3-propanediol reactant and about 10 to about 0.1 mole % of aliphaticor aromatic diacid or diester, preferably diacid. By “1,3-propanediolreactant” in the context of this invention is meant polytrimethyleneether glycol and/or poly(trimethylene-ethylene ether)glycol as describedabove for the first two classes of 1,3-propanediol based homo- orcopolyether basestock.

The aliphatic or aromatic diacids or diesters used to prepare the randompolytrimethylene ether esters are preferably aromatic dicarboxylic acidsor esters selected from the group of terephthalic acid, isophthalicacid, bibenzoic acid, naphthalic acid, bis(p-carboxyphenyl)methane,1,5-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid,4,4′-sulfonyl dibenzoic acid, p-(hydroxyethoxy)benzoic acid and estersthereof. Most preferred is terephthalic acid. US 2005-0020805 A1discloses a preferred way to prepare polytrimethylene ether glycols andesters. For use in the present invention the polytrimethylene homo- orcopolyethers preferably have a number average molecular weight of fromabout 250 to about 10,000. More preferably the number average molecularweight range will be between any two of the following possibleendpoints, including or excluding the endpoints: 250; 500; 750; 1,000;1,250; 1,500; 1,750; 2,000; 2,250; 2,500; 2,750; 3,000; 3,250; 3,500;3,750; 4,000; 4,250; 4,500; 4,750; 5,000; 5,250; 5,500; 5,750; 6,000;6,250; 6,500; 6,750; 7,000; 7,250; 7,500; 7,750; 8,000; 8,250; 8,500;8,750; 9,000; 9,250; 9,500; 9,750; and 10,000. The most preferred numberaverage molecular weight range will be from about 1,000 to about 5,000.In addition, the polytrimethylene homo- or copolyethers will preferablyhave a weight average molecular weight (Mw) to number average molecularweight (Mn) ratio (Mw/Mn ratio) of 1.7 or greater, more preferablygreater than 1.7, even more preferably 1.75 or greater, still morepreferably 1.8 or greater, even more preferably 1.85 or greater, stillmore preferably 1.9 or greater, even more preferably 1.95 or greater,and still more preferably 2.0 or greater.

The silicon-containing reactants for reaction with the polytrimethylenehomo- or copolyether glycols have the silane structure Si(W)(X)(Y)(Z)where W, X and Y are groups that are easily displaceable from silicon byreaction with water and/or alcohols, and Z is selected from the groupconsisting of: C₁-C₂₀ linear or branched alkyl groups; cycloaliphaticgroups; aromatic groups, each being optionally substituted with a memberselected from the group consisting of O, N, P and S; and groups that areeasily displaceable from silicon by water and/or alcohol. Examples ofmoieties directly bonded to silicon which are easily displaceable byreaction with alcohol or water include but are not limited to alkoxy,aryloxy, acyloxy, amide, carbamate, urea, ketoximine, amine, halogen andimidazole.

Preferred moieties which are easily displaceable by reaction with wateror alcohols are alkoxy and aryloxy groups having from 1 to 20 carbonatoms. Illustrative of alkyl and aryl radicals bound to oxygen in thealkoxy and/or aryloxy radicals are, for example, alkyl radicals, e.g.,methyl, ethyl, propyl, butyl, octyl, etc.; aryl radicals, e.g., phenyl,tolyl, xylyl, naphthyl, etc.; aralkyl radicals, e.g. benzyl andphenylethyl; olefinically unsaturated monovalent radicals, e.g. vinyl,allyl, cyclohexenyl, etc.; and cycloalkyl radicals such as cyclohexyl,cycloheptyl, etc. More preferred moieties which are easily displaceableby reaction with water or alcohols are C₁-C₁₂ alkoxyl groups, even morepreferred are C₁-C₃ alkoxyl groups, and most preferred are ethoxylgroups.

As indicated above, the Z moiety in the silicon-containing reactant offormula Si(W)(X)(Y)(Z), can also be a member of the group consisting ofC₁-C₂₀ linear or branched alkyl groups, cycloaliphatic groups, aromaticgroups, each being optionally substituted with a member selected fromthe group consisting of O, N, P and S. Examples include, but are notlimited to methyl, ethyl, isobutyl, octyl, isooctyl, vinyl, phenyl andcyclohexyl. Examples of the silanes operable in the invention include,but are not limited to: tetramethoxysilane, tetraethoxysilane,tetrapropoxysilane, methyltrimethoxysilane, methyltriethoxysilane,methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,ethyltripropoxysilane, propyltrimethoxysilane, propyltriethoxysilane,propyltripropoxysilane, isobutyltrimethoxysilane,isobutyltriethoxysilane, isobutyltripropxysilane, octyltrimethoxysilane,octyltriethoxysilane, octyltripropoxysilane, isooctyltrimethoxysilane,isooctyltriethoxysilane, isooctyltripropoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane,phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane.The tetraalkoxysilanes (also known as tetraalkyl orthosilicates) arepreferred. Most preferred is tetraethoxysilane, or tetraethylorthosilicate.

The silylation reaction of the polytrimethylene homo- or copolyetherglycols with the silicon-containing reactants is readily carried out,usually at elevated temperatures of from about 80 to about 150° C.,while removing volatile by-products. Generally at least about 1 mole ofreactant is used for each equivalent of hydroxyl groups in the homo- orcopolymer. More volatile reactants, e.g. tetraethyl orthosilicate, canbe used in excess, and any excess can be removed at the end of reactionby vacuum distillation. The reaction is conveniently carried out in asolvent. Aromatic hydrocarbons such as xylene are preferred solvents;however, any solvent that is inert to the reactants and convenientlyremovable is satisfactory. General conditions for carrying out thereaction of silanes with polyols are disclosed in U.S. Pat. No.6,080,816. Depending upon the reactivity of the silicon-containingreactant, it may be desirable to employ a catalyst for the silylationreaction. In cases where a catalyst is necessary yet it is desirable tohave product essentially free of catalysts, catalysts which can beeffectively and conveniently removed from the products are preferred.Particularly useful are heterogeneous catalysts such as fluorosulfonicacid (NAFION® NR-50; DuPont), which can be easily separated from theproduct. Other preferred catalysts are volatile catalysts such astrifluoroacetic acid, amines or thermofugitive catalysts such atetraalkylammonium hydroxides, which can be substantially removed by apostheating step. Many other useful catalysts can be employed andremoved after reaction by passing the product through appropriate ionexchange or absorbing media. Examples of other useful catalysts includebut are not limited to medium and strong acids or bases such as sulfonicacids, alkali bases; ammonium salts; tin containing compounds such asdibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate,dibutyltin dioxide; titanates such as tetraisopropyl titanate,tetrabutyl titanate (DuPont T Y Z O R, aluminum titanate, aluminumchelates, zirconium chelate and the like. The reaction of thepolytrimethylene homo- or copolyether glycols with thesilicon-containing reactants involves replacement of at least a portionof the hydroxyl end groups of the polyether with silicon-containing endgroups having the formula: —O—Si(X)(Y)(Z), wherein X and Y and Z are asdescribed above. Thus the product will consist largely of polymer orcopolymer with these end groups. However, secondary reactions are alsopossible where the end groups can further react with hydroxyl groups onone or more additional molecules of homo- or copolyether to displace X,Y or Z groups and yield chain extended or branched structures. In thatcase, in addition to X, Y and Z being groups that are easilydisplaceable from silicon by reaction with water and/or alcohols, alkylgroups, aromatic groups or cycloaliphatic groups as described above,they may also be residues of the starting polymer or copolymer. Ingeneral then, when X, Y and Z are —OR₁, —OR₂ and —OR₃, R1, R2 and R3,which can be the same or different, can be selected from the groupconsisting of C1-C12 monovalent hydrocarbon radicals, —PX OH, and —PXOSi(—OR₁)(—OR₂)(—OR₃), where PX represents the polymer chain ofpolytrimethylene ether, poly(trimethylene-ethylene ether), or randompoly(trimethylene ether ester). To illustrate the above with a specificexample, in the case where the starting polytrimethylene homo- orcopolyether glycol is polytrimethylene ether glycol, and thesilicon-containing reactant is tetraalkyl orthosilicate, Si(OR)₄, X, Yand Z can be, in addition to alkoxyl groups —OR, the following:—O(CH₂CH₂CH₂O—)nH and—O(CH₂CH₂CH₂O—)nSi(X)(Y)(Z),where X, Y and Z are alkoxy groups or residues of the starting polymeror copolymer and n is from 2 to about 200. Analogous structures may bewritten for poly(trimethylene-ethylene ether)glycol and randompoly(trimethylene ether ester), silicon-containing reactants containingother groups easily displaceable by water or alcohols. To the extentthat this chain extension and/or branching occurs, it will increase thedegree of polymerization and molecular weight of the product.

The functionality (i.e., reactive functional groups per polymer chain)of the polytrimethylene homo- or copolyether glycol starting materialsis 2. The silylation reaction described herein may increasefunctionality. For example, when the silicon-containing reactant istetraalkyl orthosilicate, polymer having silicon groups on both chainends will have its functionality increased from the original 2 to atleast 6 for the linear homo- or copolyether starting materials, andpossibly even higher than 6 in the branched materials described above.The increase in functionality is due to the reactivity to water andalcohols of the alkoxyl groups on silicon.

The reactivity and increased functionality of the products of theinvention make them particularly useful as crosslinking agents fororganic polyols, in particular organic polyols that are film formingcompounds. These crosslinked organic polyols provide compositions suchas coatings, adhesives, inks, and sealants. Preferably, the polyol foruse in these applications is one selected from the group consisting ofacrylics, cellulosics, urethanes, polyesters, and epoxides.

An example of these crosslinking applications for the silicon-containingpolytrimethylene homo- or copolyethers of the invention is as acrosslinking component of UV curable inks and coatings. In UV curablecationic coatings, photoinitiators generate cationic catalyst species,which then function as catalysts for cationic polymerization. Typicalmonomers/oligomers for the cationic coatings are vinyl ethers, propenylethers, or epoxide containing compounds. Vinyl ethers, propenyl ethersor epoxide-containing compounds, in particular cycloaliphatic epoxides,are the major reactive monomers/oligomers used for cationic UV curedcoatings, as discussed by Wu et al. Polymer, 40 (1999), pp. 5675-5686.Two types of crosslinkers are widely used for these coatings, lowmolecular weight alcohols and high molecular weight polyols.Polytrimethylene homo- or copolyether glycols can be used as acrosslinker for cationic UV curable coatings. However, they have afunctionality of only 2. On the other hand, their silicon-containingderivatives have functionalities greater than the original 2. Thereforethey would be expected to function as crosslinkers at lower levels thanthe original glycols, with the possible added advantage of lowerviscosity due to replacement of at least some of the hydrogen bondinghydroxyl groups with siloxane groups.

A further advantage of the silicon-functionalized polytrimethylene homo-or copolyethers as compared to their parent homo- or copolyethersglycols for use in coatings and inks is the reduced viscosity due to thereplacement of the hydroxyl groups by the Si groups. The viscosity canbe fine tuned by the extent of siloxane functionalization and by themolecular weight of the starting polymer or copolymer.

The invention is illustrated in the following examples. All parts,percentages, etc., referred to in this application (including theexamples) are by weight unless otherwise indicated.

EXAMPLES

The 1,3-propanediol utilized in the examples was prepared by biologicalmethods and had a purity of >99.8%. Polytrimethylene ether glycol ofvarying molecular weights used in the examples was prepared by themethods described in U.S. Patent 25 Application Publication No.2002/0007043.

Example 1

This example illustrates preparation of siloxane functionalized1,3-propanediol. 1,3-Propanediol (36.5 g) was added to a 500 ml., fourneck round bottom flask. The flask was equipped with a mechanicalstirrer (60 rpm), a reflux condenser with cooling water, a thermocouplefor temperature monitoring and a nitrogen sparging tube which providednitrogen gas flow of 263 ml/minute. Tetraethyl orthosilicate (299.6 g,1.44 mole, 98% purity), 35 g of o-xylene and 1.17 g of dibutyltindilaurate were transferred into the reaction flask using syringes. Themixture was refluxed at 97-102° C. for 4 hours. Then the xylene andexcess tetraethyl orthosilicate were removed in vacuum using a BUCHIVACUUM ROTOVAPOR at 75° C. for 5 hours at 12 Torr. The residual liquidproduct was analyzed by NMR for identification of composition. Based onthe NMR results, the reaction yield was 83%.

The FT-IR spectrum of the siloxane functionalized 1,3-propanediol wasobtained. The IR spectra of pure tetraethyl orthosilicate and thesiloxane functionalized product were very similar. The spectra of bothconfirmed the presence of the absorption bonds of: methyl groups (CH₃,asym, stretching) at 2975 cm⁻¹, two different methylene groups (CH₂,stretching, sym and asym) at 2929 and 2888 cm⁻¹, Si—O—C (asym) at 1168,and 1072 cm⁻¹, Si—O at 958 cm⁻¹, Si—O—C at 786 cm⁻¹ (sym), OH at 3450and 3550 cm⁻¹ (hydroxyl groups were detected in spectrum of theresultant due to the presence of non-reacted 3G, and C—O—C at 1100-1070cm⁻¹ (overlapping with Si—O—C).

There are 8 C—H bonds due to CH2 groups in the spectrum of tetraethylorthosilicate and 12 C—H bonds due to similar CH2 groups in the siloxanefunctionalized 1,3-propanediol. On the other hand, there are 12 C—Hbonds due to CH3 groups in tetraethyl orthosilicate and also 12 C—Hbonds due to similar CH3 groups in the siloxane functionalized1,3-propanediol. Therefore, the ratio of numbers of C—H bonds in CH3groups to the numbers of C—H bonds in CH2 groups in tetraethylorthosilicate (12/8) was greater than the same ratio in resultantsiloxane functionalized 1,3-propanediol (12/12). This ratio can becalculated by dividing the intensity of absorption bonds in the CH3 peak(2975 cm⁻¹, CH₃, asym) to the intensity of any C—H absorption bonds dueto CH2 (for example, peak at 2888 cm⁻¹, CH2 asym). As expected, thisratio in tetraethyl orthosilicate was greater than the similar ratio inthe siloxane functionalized 1,3-propanediol.

The H-NMR spectrum of tetraethyl orthosilicate showed the presence of anethyl group (CH₃, 6 1.9-1.3; CH₂, 6 3.8-3.9). In an ethyl group themultiplicity of the peak related to CH3 is triplet, and the multiplicityof the peak related to CH2 is quartet. Furthermore, the ratio of theintegration related to CH2 groups (6 3.8-3.9) to the integration relatedto CH3 groups (6 1.3-1.9) was 66.6%. This number was expected since thenumbers of protons in the tetraethyl orthosilicate CH2 groups is 8, andthe numbers of protons in CH3 groups is 12 (the ratio is equal to 8/12which is 66.6%). In the H-NMR spectrum of siloxane functionalized1,3-propanediol there were similar peaks for ethyl group (CH₃, 61.9-1.3, CH₂, 6 3.8-3.9). Because of the two different CH2 groups insiloxane functionalized 1,3-propanediol (CH₂CH₂O and OCH₂CH₃) and theslightly different environments of ethyl groups in siloxanefunctionalized 1,3-propanediol, the triplet and quartet structures at 63.8-3.9 and 1.3-1.9 displayed a more complex splitting pattern. Finally,there were some other weak peaks, which probably represent the presenceof components such as the aliphatic CH3 and aromatic CH2 groups inxylene, the middle and end CH2 group in 1,3-propanediol, and the CH2group between two carbons in the siloxane functionalized1,3-propanediol.

The C-NMR spectra were the most useful analysis method for siloxanefunctionalized 1,3-propanediol structure determination. C-NMR of puretetraethyl orthosilicate clearly indicated the 1/1 (4/4) ratio of CH2carbons (−59) to CH3 carbons (−18). This ratio changed to 111.67/100.00in the C-NMR of resultant siloxane functionalized 1,3-propanediol.Consequently, the expansion of CH2 peak at −59. split the peak into twoseparate peaks with different integration (however, area of 111.67covers both peaks). The peak with shorter integration might be due tocarbons at CH₂CH₂O groups and the adjacent peak might be due to carbonsin CH2 groups at OCH₂CH₃. The carbon resonance for the end CH2 groups in1,3-propanediol appeared at −59.9. The yield of the reaction wascalculated based on the area under peaks (integration) of CH₃, CH2 ofthe siloxane functionalized 1,3-propanediol and tetraethyl orthosilicateand CH₂OH of 1,3-propanediol.

Example 2

This example illustrates preparation of siloxane functionalizedpolytrimethylene ether glycol of approximately 1,000 number averagemolecular weight.

The procedure described in Example 1 was used for silylation ofpolytrimethylene ether glycol of about 1,000 number average molecularweight. In this example, polytrimethylene ether glycol (258.9 g)(Mn=1079, 0.24 mole), 149.7 g tetraethyl orthosilicate (0.72 mol), 38.3g xylehe and 1.3 g dibutyltin dilaurate were mixed in the reactionflask. The mixture was allowed to react at reflux temperature of 128° C.for 4 hours, followed by vacuum separation of the xylene, the ethanolbyproduct and the excess tetraethyl orthosilicate at 90° C. at 10 Torrfor 5 hours.

Proton and carbon-13 NMR analyses indicated that the product had theoriginal polytrimethylene ether backbone structure, but all hydroxylends had been converted to siloxane groups. The number average molecularweight was found to have increased from 1,079 to 1,594, corresponding toan increase in degree of polymerization (DP) from 18 to 21. This 17%increase in DP demonstrates chain extension or branching due to thesecondary reaction from the siloxane endgroups. Light scattering and gelpermeation chromatography (GPC) showed that the product sample had amolecular weight dispersity of 2.

Silicone NMR of the product indicated that there were two Si signals inpeak intensity ratio of 6 to 1, thus confirming the minor Si sidereaction for chain extension or branching.

Based on the NMR molecular weight data, the siloxane functionalizationof polytrimethylene ether glycol underwent the following reaction:H

OCH₂CH₂CH₂

_(n)OH+2Si(—OCH₂CH₃)₄Si(—OCH₂CH₃)₄—→Si(—OCH₂CH₃)₃—O—(CH₂CH₂CH₂O—)_(n)Si(—OCH₂CH₃)₃+2+minorchain extended and branched product.

The molecular weight and thermal transitions of the product from thisexample are shown in Table 1.

TABLE 1 Siloxane Functionalization of Polytrimethylene ether Glycol ofApproximately 1,000 Molecular Weight Mn by Tm^(a) Tg^(b) Tc^(c) SampleNMR DP (° C.) (° C.) (° C.) Wt % Si Starting 1,079 18 15.6 −80.8 37.6 0Glycol Siloxane 1,594 21 −3.34 −88.9 −57.2 4.6 Product ^(a)meltingpoint, ^(b)glass transition temperature, ^(c)crystallization temperature

Example 3

This example illustrates preparation of siloxane functionalizedpolytrimethylene ether glycol of about 2,000 number average molecularweight.

The same procedure described in Example 1 was used for siloxanefunctionalization of polytrimethylene ether glycol of about 2,000molecular weight. Polytrimethylene ether glycol (243.9 g) (Mn=2,032,0.12 mol), 74.8 g of tetraethyl orthosilicate (0.36 mol), 30.7 g xyleneand 1.1 g dibutyltin dilaurate were mixed in the reaction flask. Themixture was allowed to reflux at 141° C. for 4 hours, followed by vacuumseparation of xylene, the ethanol byproduct and the excess tetraethylorthosilicate at 90° C. and 10 Torr for 5 hours.

Proton and carbon-13 NMR analyses showed that the resultant polymer hadthe original polytrimethylene ether polymer backbone structure, and thatall of the hydroxyl end groups had been converted to siloxane groups.The number average molecular increased from 2,032 to 3,269,corresponding to an increase of degree of polymerization (DP) from 34 to50. This increase in DP of 49%, indicates the substantial chainextension and/or branching due to the secondary reaction from thesiloxane endgroups under the reaction conditions shown in this example.

The molecular weight and thermal transitions of the product from thisexample are shown in Table 2.

TABLE 2 Siloxane Functionalization of Polytrimethylene ether Glycol ofApproximately 2,000 Molecular Weight Mn by Tm^(a) Tg^(b) Tc^(c) SampleNMR DP (° C.) (° C.) (° C.) Wt % Si Starting 2,032 34 18.2 −76.3 not 0Glycol available Siloxane 3,269 50 8.14 −88.6 −47.5 2.8 Product^(a)melting point, ^(b)glass transition temperature, ^(c)crystallizationtemperature

Example 4

This example illustrates the change in viscosity that occurs uponsiloxation of 1,3-propanediol based homo- or copolyether. For examples1, 2 and 3 above, viscosities were determined on starting glycols andthe siloxane-treated products. The data are presented in Table 3.

TABLE 3 Viscosity at Viscosity at Example Sample 40° C. (cP) 60° C. (cP)1 Starting 21.0 10.3 Glycol 1 Siloxane 1.8 1.3 Product 2 Starting 207.992.7 Glycol 2 Siloxane 141.0 81.4 Product 3 Starting 666.2 295.6 Glycol3 Siloxane 1271.0 643.3 Product

It is believed that in examples 1 and 2 the viscosity decreases becauseafter the reaction with siloxane, the hydroxyl groups in the polymerends are converted to siloxane groups, and the reduction of the hydrogenbonding and the interactions of OH functions leads to lower viscosity.In examples 1 and 2, the starting molecular weight is relatively low,and the secondary siloxane reaction, which leads to branching andcrosslinking, is relatively minor. This is demonstrated by the data inTable 1 indicating that in example 2, the DP changes from 18 to only 21.In example 3, however, the starting polyglycol molecular weight ishigher, and the secondary reaction becomes more competitive. As shown inTable 2, the DP changes from 34 to 50 after the siloxane reaction.Apparently, in this example the branching and crosslinking of thepolymer due to the secondary reactions more than compensates for the OHinteraction effect.

Determination of Degree of Polymerization and Molecular Weight forExamples 1 and 2

Carbon NMR can distinguish the carbons corresponding to the end ethergroups beside the siloxane groups (B1) from that of the middle ethergroups (B), and thus it was possible to calculate the molecular weightby comparing the integral area of these two peaks. The integral areascorrespond to n carbons (B) for the middle ether groups as well as 2carbons (B1) for the end ether groups beside the siloxane groups.

Therefore, the integral area of B associated with n carbons=Integralarea of B1 associated with 2 carbons=n/2

Since n represents the number of middle ether groups, the total numbersof middle ether groups plus the two end ether groups beside the siloxanegroups provides the degree of polymerization: DP=n+2

The number average molecular weight will be given by:Mn=(DP×58.08)+342.16

For example, the molecular weights calculated for the products fromexamples 2 and 3 were calculated as follow:

Example 2

Relative integral area for B 519.16 Relative integral area for B1 53.06B/B1 519.16/53.06 DP 21.57 Mn (21.57 × 58.08) + 342.16 = 1594.90 g/molTotal end groups 2 × 10⁶/Mn = 1253.9 meq/kg

Example 3

C-NMR AS# 4400 Relative integral area for B 404.4 Relative integral areafor B1 16.7 B/B1 404.4/16.7 DP 50.4 Mn (50.4 × 58.08) + 342.16 = 3269.30g/mol Total end groups 2 × 10⁶/Mn = 611.8 meq/kg

The molecular weight and the degree of polymerization of thepolytrimethylene ether glycol reactants for example 2 were 1,079 and18.27, and for example 3 were 2,032 and 34.12 respectively. The totalend groups (meq/kg) can be calculated from the expression: 2×10⁶/Mn. Thetotal end groups for the polytrimethylene ether glycol reactants forexamples 2 and 3 were 1853 meq/kg, and 984.2 meq/kg respectively.

The foregoing disclosure of embodiments of the present invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formsdisclosed. Many variations and modifications of the embodimentsdescribed herein will be obvious to one of ordinary skill in the art inlight of the disclosure.

1. A process for preparing a silicon-containing polytrimethylene homo-or copolyether comprising: providing reactants comprising: (c)polytrimethylene homo- or copolyether ether glycol, wherein from about50 to 100 mole mole percent of the repeating units of thepolytrimethylene homo- or copolyether are trimethylene ether units, andwherein the polytrimethylene homo- or copolyether has an Mw/Mn ratio of1.7 or greater; and (d) a silicon-containing reactant of the formula:Si(W)(X)(Y)(Z), where W, X and Y are groups that are easily displaceablefrom silicon by reaction with water and/or alcohols, and Z is selectedfrom the group consisting of: (i) C1-C₂₀ linear or branched alkylgroups, (ii) cycloaliphatic groups, (iii) aromatic groups, each of (i),(ii) and (iii) being optionally substituted with a member selected fromthe group consisting of O, N, P and S, (iv) hydrogen, and (v) groupsthat are easily displaceable from silicon by water and/or alcohol; andcontacting said polytrimethylene homo- or copolyether ether glycolreactant in (c) with said silicon-containing reactant in (d) at elevatedtemperature.
 2. The process of claim 1, wherein the groups that areeasily displaceable from silicon by reaction with water and/or alcoholsare selected from the group consisting of alkoxy groups, aryloxy groups,acyloxy groups, amide groups, carbamate groups, urea groups, ketoximinegroups amine groups and halogens.
 3. The process of claim 1, wherein thesilicon-containing reactant is a tetraalkyl orthosilicate.
 4. Theprocess of claim 3, wherein the reactants further comprise a siloxationcatalyst.
 5. A silicon-containing polytrimethylene homo- or copolyetherether prepared by the process of claim
 3. 6. A silicon-containingpolytrimethylene homo- or copolyether prepared by the process ofclaim
 1. 7. A silicon-containing polytrimethylene homo- or copolyetherprepared by a process comprising providing and reacting (i)polytrimethylene homo- or copolyether ether glycol containing from about50 to 100 mole percent trimethylene ether units, based upon therepeating units of the polytrimethylene homo- or copolyether, selectedfrom the group consisting of (i) polytrimethylene ether glycol, (ii)poly(trimethyleneethylene ether) glycol, and (iii) randompoly(trimethylene ether ester), and (ii) at least onetetraalkoxylsilane; wherein the polytrimethylene homo- or copolyetherhas an Mw/Mn ratio of 1.7 or greater.
 8. The silicon-containingpolytrimethylene homo- or copolyether of claim 7, wherein thetetraalkoxy silane comprises tetraethoxy silane and wherein the reactingis carried out at a temperature of about 80 to about 150° C.